Improvement in paper bags and machines for cutting the same



n. w. MURPHY.` Paper-Bags and Machines for Cutting thlefSyninemf"` Patented Jan. 27,1874

No. 146,773i

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Ml. PHIITU-LITHaMAFH/G En M (naamw: #facessi `N1TED STATES RUFUS YV. MURPHY, OF ST. LOUIS, MISSOURI.

IMPROVEMENT IN PAPER BAGS AND MACHINES FOR CUTTINGTHE SAME.

` Specification forming part of Letters Patent No. 146,773., dated January 27, 1874; application filed To all whom it may concern: Be it known that I, RUFUs W. MURPHY, of the city of St. Louis and State of Missouri, have invented new and useful Improvements in Paper Bags and Knives for Cutting Out the Same, of which the following is a full, clear, and eXact description, reference being had to the annexed drawing making a part of this specification, in Which- Figure 1 represents a plan of my knife. Fig. 2 represents the blank eut by my knife. Ei gs. 3 and 4 represent the bag in its several es of completion. Similar letters indicate similar parts. My invention relates to the lower or fixed knife used in those paper-cutting machines employing a striker; and consists in giving such knife a cutting-edge of peculiar form or outline by means of serrations in the same. In the manufacture of paper-bags by machinery, one of the most important and essential points `is the pasting and subsequent closing of the lap which forms the bottom of y the bag; and since, when the sides of the bag have been folded and pasted, it is necessary, in order to close the bottom,to apply the paste on that portion of the bag which is then un! `derneath'the two sides thus folded over, it

has been found necessary to give the blank fromwhich the bag is formed a peculiar shape in order to enable this to be accomplished.

The mode most commonly adapted to this vend is to cut the blank with a projecting portion, such projection receiving the paste, and,

when turned up upon the pasted and folded sides, forming and closing the bottom of the i bag. This form of blank is objectionable, in that the projecting portion passes into, and

is seized by, the drawing-rolls ordinarily used on bag-machines before the sides of the blank,

thus frequently and almost invariably, save when the narrower blanks are used, causing y the paper to be drawn irregularly through `and under the knife. rIhe form of the knife is objectionable, for the reason that its eut is not so clean and accurate as it would be were the points of the teethin the same line.

To obtain the advantages of having the points of the teeth of the knife in the salne line, and of having the side of the blank from which the bottom of the bag is formed, and

. as shown in Fig. 3. In order to formthe botl` December 2,1873.

which is acted upon by the drawing-rolls, straight, While" the opposite side, Which,in the formed bag, constitutes the mouth, hassuitable projections for the convenient opening of the same, are the main objects sought byA me in my invention now to be described.` y y y y The knife G, Figure 1, is serrated, 13a-s seen, and is arranged beneath the strikerin the ordinary manner, a convenient modef of such arrangement,'and'f'a suitable` striker t operate in connection W1 h it, being shown i the application of MerrickfMurphy for"Im provement in Knives for Cutting Paper Bags, filed December 2, 187,3. The teeth of this knife `are of unequal `depth and Width--say, in in the proportion of oneto three--those in the center being less deep and Wide than these at the sides of the knife; butfthe points ofal th teeth are exactly in the saine line, so tha th blank cut by the knife `will be of thefshap I), Fig. 2. In forming a bagfrom this blanl it is to be folded rst in the lines .n a', and` the sides pasted by any suitable mechanism,

tom the bag must be folded `in the'line yy', Figs. 2 and 3, having been rst p rlyfpasted. New, when the paste is applied ftliehrpper side of the bag, as folded in Fig. 3, it is evident that, owing to the teeth onlthe `upper side, of the same being the larger,"sufficient` paste will pass through to the under side ofthe bag to insure a perfect adhesion of the lap when folded up, as shown in Fig. 4. The larger teeth at the mouth of the bag Will, as seen,` project beyond the smaller ones,.thus enabling the mouth to be readily opened. y

As, in some machines, thebottom lap of the y bag is turned in the opposite'direction to that shown-the paste in such being applied tothe undersideofthepartially-fblded bag,ofcoursey when blanks cut by my knife are tobe used With such machines, it will be necessary to arrange the teeth in the knife so thatthe deeper y and Wider serrations shall be in the center the blank, instead of on the sid I am Well avi-are there is no n ty in usin a knife Wit-h a serrated edge fo purpos of cutting paper, and conseqllpbl disclaim. such,broadly; but

Wlhat I do claim as mypinventio ,and desire to secure by Letters Patent, is

11V. The knife G, having its cutting-edge serofthe bz1g ,while the opposite edge constitutes rated', the teeth forming sueh serrution being the mouth of the bag, and has zt projection. of unequal depth and width7 substantially as for the openingof the same7 substantially as und for the purpose shown und described. shown and described.

2. A paper bag, formed from :1- blank havin RUFUS YV. MUR-PHY. two of its edges serrated with teeth of unequal NYitnesses: depth and Width, one of such edges being GHAS. D. MOODY,

straight, and, when folded, forming the bottom MERRICK MURPHY. 

